在功能性烯的催化性化中,通过 (II) 复合物激活C-H键的自催化
Emmanuel Ferrer Flegeau1, Christian Bruneau, Pierre H Dixneuf
1Ecole Normale Supérieure, Département de Chimie, UMR CNRS-ENS-UPMC 8640, 24 Rue Lhomond, 75231 Paris Cedex 5, France.
Journal of the American Chemical Society
|May 25, 2011
概括
((II) 催化剂通过自催化过程促进2-二中C-H键的激活. 碳氧酸的副产品加快了反应,其中涉及由碳氧酸离子进行分子间脱质.
科学领域:
- 有机金属化学 有机金属化学
- 催化剂是一种催化剂.
- 反应动力学反应动力学
背景情况:
- 研究C-H键激活机制对于开发新合成方法至关重要.
- (II) 复合物因其在有机转化中的催化特性而被广泛研究.
- 了解连接体和反应条件的作用是优化催化效率的关键.
研究的目的:
- 提供第一个动力学数据,用于通过特定的Ru (II) 复合物激活2-phenylpyridine的C-H键.
- 阐明自催化机制,并确定关键的中间体和速度决定的步骤.
- 探索碳酸共同产品和基对反应途径的影响.
主要方法:
- 使用Ru(II) ((carboxylate) ((2) ((p-cymene) 复合体与酸盐和pivalate连接体的C-H键激活反应的动态分析.
- 在不同的条件下监测反应进展,包括碳酸和基的存在.
- 反应中间体和产品的表征.
主要成果:
- C-H 键的激活是通过不可逆转的自催化过程进行的,由碳酸副产物 (HOAc或HOPiv) 催化.
- 反应速率由碳酸副产品和水加快,由基减缓.
- 通过释放的碳酸盐离子进行分子间脱被确定为C-H键激活的关键步骤,乙酸盐比pivalate更有效.
结论:
- 该研究揭示了Ru(II) 催化C-H键激活的详细机制,涉及自催化.
- 这些发现凸显了碳酸盐连接体及其相应的酸在促进催化循环中的重要作用.
- 生成的阴离子复合体对进一步的转化具有反应性,例如氧化添加.
相关概念视频
Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
Catalysis
Catalysis influences the rate of chemical reactions by providing an alternative reaction pathway with lower activation energy. A catalyst speeds up a reaction, but it is not consumed during the process. The fundamental principle of catalysis is the ability of a catalyst to alter the reaction mechanism, often introducing a more efficient pathway than the uncatalyzed process.In a catalyzed reaction, the catalyst participates directly in the reaction mechanism. It interacts with reactants to form...
Catalysis
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
Olefin Metathesis Polymerization: Overview
Recently, the development of olefin metathesis polymerization advanced the field of polymer synthesis. Simply put, the reorganization of substituents on their double bonds between two olefins in the presence of a catalyst is known as the olefin metathesis reaction. The use of metathesis reaction for polymer synthesis is called olefin metathesis polymerization.
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...


